US3679585A

US3679585A - Lubricant compositions

Info

Publication number: US3679585A
Application number: US874370A
Authority: US
Inventors: James H T Brook; Joyce Williams
Original assignee: Shell Oil Co
Current assignee: Shell USA Inc
Priority date: 1968-11-13
Filing date: 1969-11-06
Publication date: 1972-07-25
Anticipated expiration: 1989-07-25
Also published as: GB1287405A; DE1956638B2; BE741566A; FR2023175A1; NO126330B; ES373404A1; DE1956638A1; NL6916940A

Abstract

A LUBRICANT COMPRISING (1) A LUBRICATING OIL (2) AN OIL SOLUBLE SUCCINIMIDE DISPERSANT AND (3) AN OIL SOLUBLE ALCOHOL OR ESTER HAS INCREASED DISPERSANCY PROPERTIES.

Description

United States Patent U.S. Cl. 25251.5 A Claims ABSTRACT OF THE DISCLOSURE A lubricant comprising (1) a lubricating oil (2) an oil soluble succinimide dispersant and (3) an oil soluble alcohol or ester has increased dispersancy properties.

This invention relates to lubricant compositions having increased dispersancy properties. More particularly it relates to lubricant compositions in which the dispersancy effect of a succinimide dispersant additive is increased by the presence of an oil soluble alcohol or ester.

BACKGROUND OF THE INVENTION With the advent and ever increasing amount of tumpike driving and its continuous high speeds, and high engine temperature, the deposition on engine parts of oil-insoluble particles has become an extremely serious problem. This is generally true of all modern, high performance internal combustion engines. Therefore, the subject of this invention is a lubricant capable of maintaining these insoluble particles as a suspension in the oil to minimize their deposition and maintain the cleanliness of vital engine parts.

Succinirnide dispersant additives are known for dispersing insolubles formed during use of lubricating oils. It has now been found that the dispersancy effect of a succinimide dispersant additive can be increased by the preseriilce of an alcohol or ester additive in the lubricating o SUMMARY OF THE INVENTION According to the present invention, therefore, a lubricant comprises a lubricating oil; an oil soluble succinimide dispersant additive that is a reaction product of a polyamine reactant and a succinic acid reactant; and an oil soluble alcohol or ester additive. These components are defined below.

The lubricating oil is mineral or synthetic in orgin. It can be a blend of mineral and/or synthetic lubricating oils. Mineral lubricating oils can be refined from aromatic, asphaltic, naphthenic, paraflinic or mixed base crudes. The refining can give distillate lubricating oils and residual lubricating oils (for example bright stocks), which can be blended to give convenient blends. Synthetic lubricating oils can be polyolefins (for example a polyisobutene), but are preferably ester lubricating oils.

Ester lubricating oils are well known and comprise at least one ester that is a reaction product of a monohydroxy alcohol and a monocarboxylic acid; at least one ester that is a reaction product of at least one monohydroxy alcohol and a polycarboxylic acid; or at least one ester that is a reaction product of a polyhydroxy alcohol and at least one monocarboxylic acid. Mixtures of the ice esters can be used. Many different synthetic esters and mixtures of esters are available commercially and need not be described further.

For the succinimide dispersant additive, the polyamine reactant is at least one polyamine of the general formula (wherein R and R are alkylene groups having up to 7 carbon atoms or alkyl substituted alkylene groups having up to 7 carbon atoms; R and R are hydrogen atoms, alkyl groups having up to 7 carbon atoms, or amino substituted alkyl groups, the amino substituents including alkylene diamine or polyalkylene polyamine groups in which the alkylene group has up to 7 carbon atoms; and n is 0 to 5). The polyamine reactant preferably has primary, secondary and tertiary basic nitrogen atoms. Examples of polyamine reactants are alkylene-diamines (for instance ethylenediamine, propylenediamine, butylenediamine or pentylenediamine); polyalkylene-polyamines (for instance diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, di(methylethylene) triamine, dibutylenetriarnine, tributylenetetramine or dipentylenehexamine); dialkylaminoalkylamines (for instance dimethylaminomethylamine, dimethylaminoethylamine, dimethylaminopropylamine or di methylaminobutylamine); primary, secondary, tertiary amines (for instance tris (2-imino-4-aminobutyl) amine). Convenient polyamine reactants are mixtures of polyethylene polyamines, especially those containing tetraethylene pentamine. Such mixtures are conveniently prepared by reacting ethylene dichloride with ammonia.

The succinic acid reactant can be a succinic acid or a functional derivative, for example the acylhalide, anhydride or ester. The succinic acid reactant has a substantially aliphatic hydrocarbon group linked to a methylene carbon atom. This group has 30 to 200 carbon atoms. It is preferably a C alkylene polymer group, for example a polymeric group of ethylene, propylene l-butene, 2- butene or isobutene. The polymeric group conveniently has a molecular weight of 400 to 3,000, preferably 900 to 1,200 (calculated). Preferred polymeric groups are of isobutene. When it is desired to use a functional derivative of the succinic acid, the anhydride is most convenent. It can be made by reacting the polymerized alkylene hydrocarbon with maleic anhydride.

In the reaction between the succinic acid reactant and the polyamine reactant, there can be formed amides, diamides, imides and diimides. Convenient mole ratios of succinic acid reactant to the polyamine reactant are 0.5/1 to 2.5/1. Products of the reaction are available under the trademarks Lubrizol 894 or Oronite 1200. They have about weight of reaction product in a hydrocarbon carrier oil. For a lubricant of the present invention, there is conveniently 0.2 to 10 (preferably 0.5 to 5) percent weight of succinimide dispersant additive based on the lubricant.

The alcohol or ester additive of a lubricant of the pres ent invention has a boiling point such that it will either not distill or substantially not distill from the lubricant during use. The boiling point is preferably at least 200 C. (particularly at least 280 C. at atmospheric pressure). The alcohol or ester additive is monomeric and is not a polymer. It preferably has a molecular weight of 100 to 2,500 (calculated). The alcohol or ester additive can be incorporated as such or as a concentrate. If desired, it can be added with other materials to be added to a lubricant of the invention. Conveniently, there is 0.2 to 10 (preferably 0.5 to percent weight of alcohol or ester additive based on the lubricant.

The alcohol additive can be at least one monohydroxy or polyhydroxy alcohol. If desired, it can have thio atoms, for example it can be thiapentacosanol. The monohydroxy alcohols are conveniently aliphatic alcohols and may be unsaturated. These alcohols preferably have at least 9 and more preferably at least 12 carbon atoms. Examples of preferred aliphatic monohydroxy alcohols are 2-methyl-7-ethyl-undecan-4-ol; dodecanol; tridecanol; tetradecanol; pentadecanol and oleyl alcohol. Further examples of aliphatic monohydroxy alcohols are included among monohydroxy alcohols of the general formula (wherein R is an alkyl, cycloalkyl, aryl or aralkyl group; R, and R are each a hydrogen atom or an alkyl, cycloalkyl, aryl or aralkyl group; and R R and R or any two of these symbols, can jointly be part of a ring). The aliphatic monohydroxy alcohols are conveniently those in which R R, and R are each alkyl groups, and R is a methyl group. These alcohols preferably have 9 to 11, 12 to 15 or 15 to 19 carbon atoms. A mixture of them can be called a mixture of C C or C1549 branched chain alkyl alcohols. The monohydroxy alcohols of the general formula which are not aliphatic are also examples of suitable monohydroxy alcohols. When the alcohol is a polyhydroxy alcohol, it is conveniently a dihydroxy alcohol having at least 5 carbon atoms (for instance hexan-l,6-diol); a trihydroxy alcohol (for instance trimethylol propane or glycerol); a tetrahydroxy alcohol (for instance pentaerythritol); or a hexahydroxy alcohol (for instance dipentaerythritol or a hexose such as mannnitol or sorbitol). Preferred alcohols melt below 40 C.

The ester additive can be at least one ester of a low molecular weight monocarboxylic or polycarboxylic acid (e.g. C -C preferably C -C and a relatively high molecular weight alcohol, C upwards, preferably C alcohol such as Dobanol or Alfol 20+1. It is not desirable that it be an ester of a natural straight chain C1240 aliphatic fatty acid, for example oleic acid. An

ester additive for the present invention can be a reaction 1 product of a monohydroxy or polyhydroxy alcohol or a phenol with a monocarboxylic or polycarboxylic acid. The monohydroxy alcohols are preferably aliphatic. Examples are among aliphatic alcohols described earlier above for preparing ester lubricating oils. The monocarboxylic or polycarboxylic acid can be aliphatic, cycloaliphatic or aromatic. Examples are among the carboxylic acids described earlier above for preparing ester lubricating oils. Preferred carboxylic acids are naphthenic acids and alkyl substituted .benzoic, salicylic, resorcylic, anthranilic or naphthoic acids. The esters conveniently have at least 10 carbon atoms. Preferred esters melt below 70 C. Examples of esters which may be employed according to the invention are those produced by the reaction of isobutyric acid and primary aliphatic straight chain alcohols having at least twenty carbon atoms (Alfol 20+) and the reaction of salicylic acid and a mixture of such alcohols having from 12 to 15 carbon atoms (Dobanol 25). A lubricant of the present invention can also comprise one or more supplementary additives, the amounts being appropriate to the effects desired. Examples are: (a) Antifoam agents, for instance silicones;

(b) Antioxidants, for instance diarylamines (such as p,p'-dioctyldiphenylamine); substituted amines (such as phenyl a naphthylamine); substituted phenothiazines (such as N-substituted-3,7-dialkyl phenothiazines); substituted phenols (such as 4,4'-rnethylene-bis (2,6-di-t-butyl phenol; metal di-alkyldithiocarbamates metal dialkyldithiophosphates (such as zinc dialkyldithiophosphate);

(c) Anticorrosion agents, for instance Group II-A metal salts of petroleum sulfonic acids (such as a calcium 1 petroleum s-nl-fonate), especially basic form of such salts; or alkenyl succinic acids or their anhydrides;

(d) Detergents, for instance Group H-A metal salts of naphthenic acids (such as a basic calcium naphthenate), or such salts of alkyl salicylic acids) such as a mixture of calcium C1448 alkyl and dialkyl salicylates); or Group II-A metal phenates (such as a calcium salt of a condensation product of formaldehyde and octyl phenol);

(e) Extreme pressure agents, for instance organic phosphorus containing compound, such as phosphorothionates (for example triphenylphosphorotbionate); phosphates (for example triphenylphosphate or tricresylphosphate); salts of chlorinated unsubstituted phosphonic acids with amines; metal dialkyldithiocarba'amtes (such as zinc dialkyldithiocarbamates); metal dialkyldithiophosphates polyphenyls (for example chlorinated diphenyls), such as those sold under the trademark Aroclor;

(f) Metal passivators and corrosion inhibitors, for instance triazoles (such as 1,2,3-benztriazole; methyl-1,2,3- benztriazole; 3 amino 5 phenyl 1,2,4-triazole; or 3 amino 5 anilido 1,2,4 triazole); or dicarboxylic acids (such as sebacic, azelaic or adipic acid, which are particularly useful as inhibitors of lead corrosion);

[(g) Pour point depressants, for instance polymers of esters of acrylic acid or an alkylacrylic acid;

(h) Thickeners, for instance polyisobutenes; polymers of esters of acrylic acid or an alkylacrylic acid (such as lauryl methacrylate); esters of polyoxaalkylene glycols (such as fluids sold under the trademark Ucon or copolymers of propylene oxide and ethylene oxide sold under the trademark Oxilube.

The invention is illustrated by the following examples.

Example I TABLE 1 Additives: Viscosity, cs./60 C.

2% weight polyisobutenyl succinimide (Lubrizol 894) 49.6 1% weight thiapentacosanol 47.3

2% weight polyisobutenyl succinimide (Lubri-' 201 894) +1% weight thiapentacosanol 42.1

1% weight methyl salicylate 46.2 2% weight polyisobutenyl succinimide (Lubrizol 894) +1% weight methylsalicylate 43.1

EXAMPLE I! A mineral lubricating oil blend having a viscosity of 30 cs. at 60 C. was used in a commercial diesel engine until contaminated to 4.5% w. insolubles (viscosity now 49.6 cs. at 60 C.) and to the contaminated oil were added 2% W. polyisobutenyl succinimide (Lubrizol 894) and 1% w. of one of the following additives. The viscosities of the resulting composition were determined in Example I.

Methyl ester of ternary or quaternary monocarboxylic acids having at least 16 carbon atoms (Versatic 16 acids) 40.0

Methyl naphthenate mixture of primary C C alcohols Dobanol 25) Mixture of primary C -C alcohols (Dobanol -25) salicylate (described above) 42.1 Mixture of primary C -C alcohols (Dobanol 25) 42.7 iDinonyl phthalate 42.5

.Di-2-ethyl hexylazelate Z-ethylhexyl ester of ternary or quaternary unonocarboxylic acids having at least 10 carbon atoms (Versatic 10 acids) 40.0

Example III Road tests in a commercial diesel powdered automobile, using a lubricant composition according to the invention (and a control) were carried out, involving viscosity and insolubles determinations at 800 km. intervals. The following results were obtained:

COMMERCIAL LUBRICANT COM- POSITIONS (CLC) CLO plus 1% w. C12- C15 primary straight chain aliphatic (Do bauol) salicylate CLC plus 1% W. Cn-

Cn primary straight chain aliphatic (Dobanol) stearate CLC plus 1% w. thiapentacosanol The commercial lubricant composition employed in these examples consisted of a base oil blend of HVI solvent refined oils containing a combination of additives comprising superbasic alkaline earth metal alkyl salicylates, polyisobutenyl succinimide and zinc dialkyl dithiophosphate.

We claim as our invention:

1. A lubricant composition consisting essentially of a major amount of a lubricating oil and (a) from about 0.2% to about 10% by weight of the composition of an oil-soluble alkenyl succinimide dispersant additive that is the reaction product of one mole of a polyamine reactant of the formula wherein -R and R are alkylene groups having up to 7 carbon atoms or alkyl substituted alkylene groups having up to 7 carbon atoms; R and \R are hydrogen atoms, alkyl groups having up to 7 carbon atoms, or amino substituted alkyl groups in which the amino substituents are alkylene diamine or polyalkylene polyamine groups where the alkylene group has up to 7 carbon atoms; and n is 0 to 5, and from 0.5 to 2.5 moles of an alkenyl succinic acid reactant having 30 to 200 carbon atoms in the alkenyl group and -(b) from about 0.2% to about 10% by weight of the composition of an oil-soluble monomeric monohydroxy alcohol additive having at least 9 carbon atoms of the formula Ra Rr-(EJ CIEDOH in which R is an alkyl, cycloalkyl, aryl or aralkyl group; R and R are each a hydrogen atom or an alkyl, cycloalkyl, aryl or aralkyl group; and R R and [R or any two of these can jointly be part of a ring, or an oilsoluble monomeric ester additive that is the reaction product of a C -C monocarboxylic acid and an alkanol having suificient carbon atoms such that the molecular weight of said ester is at least 100.

2. The composition of claim 1 in which the alkanol reactant used in producing the oil soluble ester additive has from 12 to 20 carbon atoms.

3. The composition of claim 1 in which the oil soluble alcohol or ester additive has a boiling point greater than 200 C.

4. The composition of claim 1 in which the reaction product of the polyamine reactant and the alkenyl succinic acid reactant is polyisobutenyl succinimide.

5. The composition of claim 4 in which the polyisobutenyl succinimide forms 2% by weight of the composition and the oil soluble alcohol or ester additive forms 1% by weight of the composition.

6. The composition of claim 1 in which the oil soluble alcohol or ester additive forms from about 0.5% to about 5% by weight of the composition.

7. The composition of claim 6 in which the acid from which the soluble ester additive is derived is a naphthenic, salicylic, resorcylic, anthranilic, naphtholic or alkyl substituted 'benzoic acid.

8. The composition of claim 6 in Which the oil soluble additive contains at least twelve carbon atoms.

7 8 9. The composition of claim 1 in which the alkanol 3,331,776 7/1967 Krukziener 252-56 reactant used in producing the oil-soluble ester additive 3,381,022 4/1968 Le Suer 25256 R has at least 8 carbon atoms. 3,405,065 10/ 1968 Goodwine 252-515 A References Cited 5 DANIEL E. Primary Examiner UNI STATES PATENTS W. J. SHINE, Assistant Examiner 3,202,678 8/1965 Stuart et al 25251.5 A Us 3,219,666 11/1965 Norman (it al. Z5251.5 A 252 52 56 R, 57 V 3,288,714 11/1966 Osuch 25257 0